Species Profile

Atlantic Sturgeon St. Lawrence populations

Scientific Name: Acipenser oxyrinchus
Other/Previous Names: Atlantic Sturgeon (Great Lakes / St. Lawrence populations)
Taxonomy Group: Fishes
COSEWIC Range: Quebec, Atlantic Ocean
COSEWIC Assessment Date and Status Change: May 2011
COSEWIC Status: Threatened
COSEWIC Status Criteria: D2
COSEWIC Reason for Designation:

This large-bodied, slow-growing, and late-maturing fish consists of a small breeding population spawning within a relatively small area. The species is exploited in a regulated commercial fishery, but limited monitoring of the effects of this fishery make the viability of this population highly uncertain.
COSEWIC History of Status Designation: Designated Threatened in May 2011.
SARA Status: No schedule, No Status
Date of Listing (yyyy-mm-dd):

No schedule - No Status

Individuals of this species may be protected under Schedule 1 under another name; for more information see Schedule 1, the A-Z Species List, or if applicable, the Related Species table below.

Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.

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Quick Links: | Photo | Description | Habitat | Biology | Threats | Protection | National Recovery Program | Documents

Image of Atlantic Sturgeon

Atlantic Sturgeon Photo 1



The Atlantic Sturgeon is a large-bodied, slow-growing and late-maturing anadromous fish, which lives and grows in brackish, salty water, but spawns in fresh water. The largest fish to be captured in the St. Lawrence River (160 kg or 350 lb) was estimated to be about 60 years old.


Distribution and Population

According to the Committee on the Status of Endangered Wildlife in Canada, Atlantic Sturgeon found in Canadian waters form two distinct populations: the St. Lawrence and Maritimes populations. The Atlantic Sturgeon, St. Lawrence populations, is mainly found east of Trois-Rivières, into the Estuary and past the Gulf of St. Lawrence, into the Atlantic up until Ungava Bay in the north, and along the northeastern coast of Newfoundland in the south. The species gathers in areas between Québec City and Petite-Rivière-Saint-François to rear and feed their young, and potentially so adults can spawn, rest and feed as well. The current population size of Atlantic Sturgeon, St. Lawrence populations, has never been formally established but the population of mature adults is estimated at between 500 and 1000 individuals.



The Atlantic Sturgeon lives and grows in brackish and salty water, but spawns in fresh water. The transition zone between fresh water and salt water in the St. Lawrence estuary is home to groups of benthic prey preferred by the Atlantic Sturgeon and is an important habitat for the breeding and feeding of juveniles. The Atlantic Sturgeon feeds primarily on benthic invertebrates, although large juveniles and adults also feed on small fish.



In the St. Lawrence River, males reach sexual maturity between the ages of 16 and 26, while females may reach maturity around age 27 or 28. Because of its large size, the female Atlantic Sturgeon is extremely fertile. A 148-kg female was reportedly captured in the St. Lawrence River with 41.4 kg ovaries containing about 3,700,000 eggs. The Atlantic Sturgeon does not spawn every year. Males probably reproduce every 3 to 4 years, while this interval is longer for females. In the St. Lawrence River, spawning occurs in June and July, after which the adults migrate further downstream in the Estuary and the Gulf. Juveniles begin their migration once they have reached 80 to 120 cm.



The main threats to the Atlantic Sturgeon are commercial fishing and the degradation and loss of habitat. Dredging could constitute a major threat, especially in juvenile feeding areas. Marine and fresh water pollution was also identified as a potential threat to the Atlantic Sturgeon's habitat.



Federal Protection

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.



PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.

4 record(s) found.

COSEWIC Status Reports

  • COSEWIC Status Report on the Atlantic Sturgeon Acipenser oxyrinchus in Canada (2011-09-09)

    The Atlantic Sturgeon is a member of one of the oldest groups of living fishes. All sturgeon are characterized by having an internal skeleton composed of cartilage, a bottom-oriented mouth bordered with fleshy barbels, and a set of bony projections or “scutes” occurring in rows along the body. The Atlantic Sturgeon is recognized by a particular arrangement of the scutes and an elongate body with a slightly upturned snout. The Atlantic Sturgeon is an anadromous species that resides and matures in the sea, but spawns in freshwater, which also serves as juvenile rearing habitat. Mature female Atlantic Sturgeon attain an average total length of 2 - 3 m and weigh between 100 - 200 kg; mature males are smaller at 1.4 - 2.1 m total length and weigh 50 - 100 kg. Genetic information suggests both regional and population-level structure and the existence of two designatable units (DUs): St. Lawrence River and Maritimes DUs.

Response Statements

  • Response Statement - Atlantic Sturgeon, St. Lawrence populations (2011-12-08)

    This large-bodied, slow-growing, and late-maturing fish consists of a small breeding population spawning within a relatively small area. The species is exploited in a regulated commercial fishery, but limited monitoring of the effects of this fishery make the viability of this population highly uncertain.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2010 - 2011 (2011-09-09)

    Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings during the past year assessing the status or reviewing the classification of a total of 92 wildlife species.

Consultation Documents

  • Atlantic Sturgeon Consultations on listing under the Species at Risk Act (St. Lawrence populations) (2014-11-17)

    Warning : The "Save File" and "Submit" functions of the PDF questionnaire are only active for users of Internet Explorer. If you are using another browser, here are the instructions: 1- save the empty PDF questionnaire on your computer; 2- close your browser; 3- open the PDF with Acrobat Reader and fill it out; 4- click on the "Submit" button or attach the filled out PDF questionnaire to an email. You can also submit your comments by using the "Comment form" below, by sending us your answers directly in an email or by printing your completed form and mailing it (see contact information below). Before deciding whether the St. Lawrence populations of Atlantic Sturgeon will be added to the List of Wildlife Species at Risk, we would like your opinions, comments and suggestions regarding the possible ecological, cultural and economic impacts of listing these populations under the Species at Risk Act.
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